Detector apparatus with detachable evaluation unit

ABSTRACT

A detector apparatus includes a scattered radiation grid; a scintillator unit for converting X-rays into a light quantity; an evaluation unit for converting the light quantity into electric signals; and a module-receiving appliance. The scintillator unit and the scattered radiation grid are mechanically connected to the module-receiving appliance via a first connection and the evaluation unit is mechanically connected to the module-receiving appliance via a second connection, independent of the first connection. The evaluation unit, the scintillator unit and the scattered radiation grid are aligned with respect to one another such that light quantity, when emitted from sub-regions of the scintillator unit, is registered by sub-regions of the evaluation unit.

PRIORITY STATEMENT

The present application hereby claims priority under 35 U.S.C. §119 toGerman patent application number DE 102016204457.5 filed Mar. 17, 2016,the entire contents of which are hereby incorporated herein byreference.

FIELD

At least one embodiment of the invention generally relates to a detectorapparatus and a medical device, wherein the scintillator unit isconnected to the evaluation unit such that the scintillator unit can befixed in the detector apparatus independently of the evaluation unit.

BACKGROUND

Integrated indirectly-converting X-ray detectors can be used in X-rayimaging, for example in computed tomography, angiography or radiography.The X-rays or photons can be converted in indirectly-converting X-raydetectors into light by a suitable converter material and into electricpulses by way of photodiodes. Frequently scintillators, for example GOS(Gd₂O₂S), CsJ, YGO or LuTAG are used as the converter material.Scintillators are in particular used in medical X-ray imaging in theenergy range of up to 1 MeV.

So-called indirectly-converting X-ray detectors, so-called scintillatordetectors, are typically used in which the X-rays or gamma rays areconverted into electric signals in two stages. In a first stage, theX-ray or gamma quanta are absorbed in a sub-region of the scintillatorunit and converted into optical visible light, a light quantity; thiseffect is called luminescence. The light excited by luminescence is thenconverted in a second stage by a first photodiode optically coupled tothe scintillator unit in a sub-region of an evaluation unit into anelectric signal, read out via an electronic evaluation or readout deviceand then forwarded to a computing unit.

The sub-regions of the scintillator unit and the evaluation unit are asa rule subdivided such that a sub-region of the evaluation unit isassigned to each sub-region of the scintillator unit. This is thenreferred to as a pixelated X-ray detector. X-ray detectors such as thoseused in computed tomography, for example, are typically made up of aplurality of modules, which comprise a scattered radiation grid, ascintillator unit, an evaluation unit with photosensors or photodiodes,for example as a photodiode array, and with electronic units forconverting the analog signal into digital information and a mechanicalcarrier. The scattered radiation grid is used to suppress scatteredradiation. The mechanical carrier is used to mount the scatteredradiation grid, the scintillator unit and the evaluation unit. Thescattered radiation grid, scintillator unit and photodiode are typicallypixelated in the same way in two directions, for example intorectangular or square pixels. In order to achieve good dose utilizationand simultaneously low crosstalk between the pixels, the scatteredradiation grid, scintillator unit and photodiode are positioned veryexactly with respect to one another when assembling the modules.

When assembling the modules, the scintillator unit or the scintillatorarray are permanently attached to the photodiode array with the aid ofan optical adhesive and aligned at the same time. Both are then securedtogether on the mechanical carrier or the mechanical module unit. Thescattered radiation grid is then also permanently connected to themodule, either by bonding with the scintillator array or by way ofmechanical fixation on the mechanical carrier, wherein once againoptimal positioning with respect to the scintillator array is to beachieved. Finally, the modules pre-assembled in this way are secured inthe housing of the detector or the module-receiving appliance. In thiscase, suitable measures, for example stop surfaces, locating pins or thelike ensure that the grip openings of the scattered radiation grid arealigned as well as possible with the tube focus.

Publication DE 102010062192 B3 discloses a 2D collimator for a radiationdetector with 2D collimator modules arranged in series, wherein adjacent2D collimator modules are glued together to establish a fixed mechanicalconnection to facing module sides and wherein, on their free-remainingside, the outer 2D collimator modules have a retaining element formounting the 2D collimator opposite a detector mechanism.

Publication DE 102010020610 A1 discloses a radiation detector comprisinga scintillator with septa for separating scintillator elements arrangedalongside one another and a collimator with webs for forming laterallyenclosed radiation channels, wherein the webs are inserted into thesepta in order to avoid crosstalk between adjacent scintillatorelements.

Publication DE 10335125 B4 discloses a method for producing aluminescent body for an X-ray detector, in particular for X-ray computedtomography scanners, which is made of a ceramic with the generalcomposition (M_(1-x)Ln_(x))₂O₂S, M being at least one element selectedfrom the group: Y, La, Sc, Lu and/or Gd, and Ln being at least oneelement selected from the group: Eu, Ce, Pr, Tb, Yb, Dy, Sm and/or Ho.

SUMMARY

The inventors have recognized a problem that the scintillator unit andthe evaluation unit are inseparably connected so that, for example, whenthe evaluation unit is replaced, it is also necessary to replace thescintillator unit.

At least one embodiment of the invention discloses a detector apparatusand a medical device, which facilitate simplified repair andmaintenance.

At least one embodiment of the invention is directed to a detectorapparatus; and at least one embodiment of the invention is directed to amedical device.

At least one embodiment of the invention relates to a detector apparatuscomprising a scattered radiation grid, a scintillator unit forconverting X-rays into a light quantity, an evaluation unit forconverting the light quantity into electric signals, and amodule-receiving appliance. The scintillator unit and the scatteredradiation grid are mechanically connected to the module-receivingappliance via a first connection. The evaluation unit is mechanicallyconnected to the module-receiving appliance via a second connectionwhich is independent of the first connection. The evaluation unit, thescintillator unit and the scattered radiation grid are aligned withrespect to one another such that the light quantity emitted fromsub-regions of the scintillator unit is registered by sub-regions of theevaluation unit.

At least one embodiment of the invention further relates to a medicaldevice comprising a detector apparatus according to the invention. Atleast one embodiment of the invention, the medical device is a computedtomography scanner. The advantages of the detector apparatus accordingto at least one embodiment of the invention can be transferred to themedical device. The detector apparatus for the medical device canadvantageously be produced less expensively. Repairs to the detectorapparatus can advantageously be less expensive.

BRIEF DESCRIPTION OF THE DRAWINGS

The following explains example embodiments of the invention in moredetail with reference to the drawings, which show:

FIG. 1 a schematic view of a detector apparatus according to theinvention in a first embodiment;

FIG. 2 a schematic view of an arrangement of the scattered radiationgrid, scintillator unit and evaluation unit according to the inventionin a first embodiment;

FIG. 3 a schematic view of a according to the invention detection unitin a first embodiment;

FIG. 4 a schematic view of a detector apparatus according to theinvention in a second embodiment;

FIG. 5 a schematic view of an arrangement of the scattered radiationgrid, scintillator unit and evaluation unit according to the inventionin a second embodiment;

FIG. 6 a schematic view of a detection unit according to the inventionin a second embodiment;

FIG. 7 a schematic view of a sub-region of a scintillator unit accordingto the invention;

FIG. 8 a schematic view of a detector apparatus according to theinvention according to a third embodiment;

FIG. 9 a schematic view of a according to the invention arrangement ofthe scattered radiation grid, scintillator unit and evaluation unit in athird embodiment;

FIG. 10 a schematic view of a depiction of a computed tomography scanneraccording to the invention in a first embodiment; and

FIG. 11 a schematic view of a depiction of a computed tomography scanneraccording to the invention in a second embodiment.

DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

The drawings are to be regarded as being schematic representations andelements illustrated in the drawings are not necessarily shown to scale.Rather, the various elements are represented such that their functionand general purpose become apparent to a person skilled in the art. Anyconnection or coupling between functional blocks, devices, components,or other physical or functional units shown in the drawings or describedherein may also be implemented by an indirect connection or coupling. Acoupling between components may also be established over a wirelessconnection. Functional blocks may be implemented in hardware, firmware,software, or a combination thereof.

Various example embodiments will now be described more fully withreference to the accompanying drawings in which only some exampleembodiments are shown. Specific structural and functional detailsdisclosed herein are merely representative for purposes of describingexample embodiments. Example embodiments, however, may be embodied invarious different forms, and should not be construed as being limited toonly the illustrated embodiments. Rather, the illustrated embodimentsare provided as examples so that this disclosure will be thorough andcomplete, and will fully convey the concepts of this disclosure to thoseskilled in the art. Accordingly, known processes, elements, andtechniques, may not be described with respect to some exampleembodiments. Unless otherwise noted, like reference characters denotelike elements throughout the attached drawings and written description,and thus descriptions will not be repeated. The present invention,however, may be embodied in many alternate forms and should not beconstrued as limited to only the example embodiments set forth herein.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, components, regions,layers, and/or sections, these elements, components, regions, layers,and/or sections, should not be limited by these terms. These terms areonly used to distinguish one element from another. For example, a firstelement could be termed a second element, and, similarly, a secondelement could be termed a first element, without departing from thescope of example embodiments of the present invention. As used herein,the term “and/or,” includes any and all combinations of one or more ofthe associated listed items. The phrase “at least one of” has the samemeaning as “and/or”.

Spatially relative terms, such as “beneath,” “below,” “lower,” “under,”“above,” “upper,” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. It will beunderstood that the spatially relative terms are intended to encompassdifferent orientations of the device in use or operation in addition tothe orientation depicted in the figures. For example, if the device inthe figures is turned over, elements described as “below,” “beneath,” or“under,” other elements or features would then be oriented “above” theother elements or features. Thus, the example terms “below” and “under”may encompass both an orientation of above and below. The device may beotherwise oriented (rotated 90 degrees or at other orientations) and thespatially relative descriptors used herein interpreted accordingly. Inaddition, when an element is referred to as being “between” twoelements, the element may be the only element between the two elements,or one or more other intervening elements may be present.

Spatial and functional relationships between elements (for example,between modules) are described using various terms, including“connected,” “engaged,” “interfaced,” and “coupled.” Unless explicitlydescribed as being “direct,” when a relationship between first andsecond elements is described in the above disclosure, that relationshipencompasses a direct relationship where no other intervening elementsare present between the first and second elements, and also an indirectrelationship where one or more intervening elements are present (eitherspatially or functionally) between the first and second elements. Incontrast, when an element is referred to as being “directly” connected,engaged, interfaced, or coupled to another element, there are nointervening elements present. Other words used to describe therelationship between elements should be interpreted in a like fashion(e.g., “between,” versus “directly between,” “adjacent,” versus“directly adjacent,” etc.).

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of exampleembodiments of the invention. As used herein, the singular forms “a,”“an,” and “the,” are intended to include the plural forms as well,unless the context clearly indicates otherwise. As used herein, theterms “and/or” and “at least one of” include any and all combinations ofone or more of the associated listed items. It will be furtherunderstood that the terms “comprises,” “comprising,” “includes,” and/or“including,” when used herein, specify the presence of stated features,integers, steps, operations, elements, and/or components, but do notpreclude the presence or addition of one or more other features,integers, steps, operations, elements, components, and/or groupsthereof. As used herein, the term “and/or” includes any and allcombinations of one or more of the associated listed items. Expressionssuch as “at least one of,” when preceding a list of elements, modify theentire list of elements and do not modify the individual elements of thelist. Also, the term “example” is intended to refer to an example orillustration.

When an element is referred to as being “on,” “connected to,” “coupledto,” or “adjacent to,” another element, the element may be directly on,connected to, coupled to, or adjacent to, the other element, or one ormore other intervening elements may be present. In contrast, when anelement is referred to as being “directly on,” “directly connected to,”“directly coupled to,” or “immediately adjacent to,” another elementthere are no intervening elements present.

It should also be noted that in some alternative implementations, thefunctions/acts noted may occur out of the order noted in the figures.For example, two figures shown in succession may in fact be executedsubstantially concurrently or may sometimes be executed in the reverseorder, depending upon the functionality/acts involved.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which example embodiments belong. Itwill be further understood that terms, e.g., those defined in commonlyused dictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

Before discussing example embodiments in more detail, it is noted thatsome example embodiments may be described with reference to acts andsymbolic representations of operations (e.g., in the form of flowcharts, flow diagrams, data flow diagrams, structure diagrams, blockdiagrams, etc.) that may be implemented in conjunction with units and/ordevices discussed in more detail below. Although discussed in aparticularly manner, a function or operation specified in a specificblock may be performed differently from the flow specified in aflowchart, flow diagram, etc. For example, functions or operationsillustrated as being performed serially in two consecutive blocks mayactually be performed simultaneously, or in some cases be performed inreverse order. Although the flowcharts describe the operations assequential processes, many of the operations may be performed inparallel, concurrently or simultaneously. In addition, the order ofoperations may be re-arranged. The processes may be terminated whentheir operations are completed, but may also have additional steps notincluded in the figure. The processes may correspond to methods,functions, procedures, subroutines, subprograms, etc.

Specific structural and functional details disclosed herein are merelyrepresentative for purposes of describing example embodiments of thepresent invention. This invention may, however, be embodied in manyalternate forms and should not be construed as limited to only theembodiments set forth herein.

Units and/or devices according to one or more example embodiments may beimplemented using hardware, software, and/or a combination thereof. Forexample, hardware devices may be implemented using processing circuitysuch as, but not limited to, a processor, Central Processing Unit (CPU),a controller, an arithmetic logic unit (ALU), a digital signalprocessor, a microcomputer, a field programmable gate array (FPGA), aSystem-on-Chip (SoC), a programmable logic unit, a microprocessor, orany other device capable of responding to and executing instructions ina defined manner. Portions of the example embodiments and correspondingdetailed description may be presented in terms of software, oralgorithms and symbolic representations of operation on data bits withina computer memory. These descriptions and representations are the onesby which those of ordinary skill in the art effectively convey thesubstance of their work to others of ordinary skill in the art. Analgorithm, as the term is used here, and as it is used generally, isconceived to be a self-consistent sequence of steps leading to a desiredresult. The steps are those requiring physical manipulations of physicalquantities. Usually, though not necessarily, these quantities take theform of optical, electrical, or magnetic signals capable of beingstored, transferred, combined, compared, and otherwise manipulated. Ithas proven convenient at times, principally for reasons of common usage,to refer to these signals as bits, values, elements, symbols,characters, terms, numbers, or the like.

It should be borne in mind, however, that all of these and similar termsare to be associated with the appropriate physical quantities and aremerely convenient labels applied to these quantities. Unlessspecifically stated otherwise, or as is apparent from the discussion,terms such as “processing” or “computing” or “calculating” or“determining” of “displaying” or the like, refer to the action andprocesses of a computer system, or similar electronic computingdevice/hardware, that manipulates and transforms data represented asphysical, electronic quantities within the computer system's registersand memories into other data similarly represented as physicalquantities within the computer system memories or registers or othersuch information storage, transmission or display devices.

In this application, including the definitions below, the term ‘module’or the term ‘controller’ may be replaced with the term ‘circuit.’ Theterm ‘module’ may refer to, be part of, or include processor hardware(shared, dedicated, or group) that executes code and memory hardware(shared, dedicated, or group) that stores code executed by the processorhardware.

The module may include one or more interface circuits. In some examples,the interface circuits may include wired or wireless interfaces that areconnected to a local area network (LAN), the Internet, a wide areanetwork (WAN), or combinations thereof. The functionality of any givenmodule of the present disclosure may be distributed among multiplemodules that are connected via interface circuits. For example, multiplemodules may allow load balancing. In a further example, a server (alsoknown as remote, or cloud) module may accomplish some functionality onbehalf of a client module.

Software may include a computer program, program code, instructions, orsome combination thereof, for independently or collectively instructingor configuring a hardware device to operate as desired. The computerprogram and/or program code may include program or computer-readableinstructions, software components, software modules, data files, datastructures, and/or the like, capable of being implemented by one or morehardware devices, such as one or more of the hardware devices mentionedabove. Examples of program code include both machine code produced by acompiler and higher level program code that is executed using aninterpreter.

For example, when a hardware device is a computer processing device(e.g., a processor, Central Processing Unit (CPU), a controller, anarithmetic logic unit (ALU), a digital signal processor, amicrocomputer, a microprocessor, etc.), the computer processing devicemay be configured to carry out program code by performing arithmetical,logical, and input/output operations, according to the program code.Once the program code is loaded into a computer processing device, thecomputer processing device may be programmed to perform the programcode, thereby transforming the computer processing device into a specialpurpose computer processing device. In a more specific example, when theprogram code is loaded into a processor, the processor becomesprogrammed to perform the program code and operations correspondingthereto, thereby transforming the processor into a special purposeprocessor.

Software and/or data may be embodied permanently or temporarily in anytype of machine, component, physical or virtual equipment, or computerstorage medium or device, capable of providing instructions or data to,or being interpreted by, a hardware device. The software also may bedistributed over network coupled computer systems so that the softwareis stored and executed in a distributed fashion. In particular, forexample, software and data may be stored by one or more computerreadable recording mediums, including the tangible or non-transitorycomputer-readable storage media discussed herein.

Even further, any of the disclosed methods may be embodied in the formof a program or software. The program or software may be stored on anon-transitory computer readable medium and is adapted to perform anyone of the aforementioned methods when run on a computer device (adevice including a processor). Thus, the non-transitory, tangiblecomputer readable medium, is adapted to store information and is adaptedto interact with a data processing facility or computer device toexecute the program of any of the above mentioned embodiments and/or toperform the method of any of the above mentioned embodiments.

Example embodiments may be described with reference to acts and symbolicrepresentations of operations (e.g., in the form of flow charts, flowdiagrams, data flow diagrams, structure diagrams, block diagrams, etc.)that may be implemented in conjunction with units and/or devicesdiscussed in more detail below. Although discussed in a particularlymanner, a function or operation specified in a specific block may beperformed differently from the flow specified in a flowchart, flowdiagram, etc. For example, functions or operations illustrated as beingperformed serially in two consecutive blocks may actually be performedsimultaneously, or in some cases be performed in reverse order.

According to one or more example embodiments, computer processingdevices may be described as including various functional units thatperform various operations and/or functions to increase the clarity ofthe description. However, computer processing devices are not intendedto be limited to these functional units. For example, in one or moreexample embodiments, the various operations and/or functions of thefunctional units may be performed by other ones of the functional units.Further, the computer processing devices may perform the operationsand/or functions of the various functional units without sub-dividingthe operations and/or functions of the computer processing units intothese various functional units.

Units and/or devices according to one or more example embodiments mayalso include one or more storage devices. The one or more storagedevices may be tangible or non-transitory computer-readable storagemedia, such as random access memory (RAM), read only memory (ROM), apermanent mass storage device (such as a disk drive), solid state (e.g.,NAND flash) device, and/or any other like data storage mechanism capableof storing and recording data. The one or more storage devices may beconfigured to store computer programs, program code, instructions, orsome combination thereof, for one or more operating systems and/or forimplementing the example embodiments described herein. The computerprograms, program code, instructions, or some combination thereof, mayalso be loaded from a separate computer readable storage medium into theone or more storage devices and/or one or more computer processingdevices using a drive mechanism. Such separate computer readable storagemedium may include a Universal Serial Bus (USB) flash drive, a memorystick, a Blu-ray/DVD/CD-ROM drive, a memory card, and/or other likecomputer readable storage media. The computer programs, program code,instructions, or some combination thereof, may be loaded into the one ormore storage devices and/or the one or more computer processing devicesfrom a remote data storage device via a network interface, rather thanvia a local computer readable storage medium. Additionally, the computerprograms, program code, instructions, or some combination thereof, maybe loaded into the one or more storage devices and/or the one or moreprocessors from a remote computing system that is configured to transferand/or distribute the computer programs, program code, instructions, orsome combination thereof, over a network. The remote computing systemmay transfer and/or distribute the computer programs, program code,instructions, or some combination thereof, via a wired interface, an airinterface, and/or any other like medium.

The one or more hardware devices, the one or more storage devices,and/or the computer programs, program code, instructions, or somecombination thereof, may be specially designed and constructed for thepurposes of the example embodiments, or they may be known devices thatare altered and/or modified for the purposes of example embodiments.

A hardware device, such as a computer processing device, may run anoperating system (OS) and one or more software applications that run onthe OS. The computer processing device also may access, store,manipulate, process, and create data in response to execution of thesoftware. For simplicity, one or more example embodiments may beexemplified as a computer processing device or processor; however, oneskilled in the art will appreciate that a hardware device may includemultiple processing elements or porcessors and multiple types ofprocessing elements or processors. For example, a hardware device mayinclude multiple processors or a processor and a controller. Inaddition, other processing configurations are possible, such as parallelprocessors.

The computer programs include processor-executable instructions that arestored on at least one non-transitory computer-readable medium (memory).The computer programs may also include or rely on stored data. Thecomputer programs may encompass a basic input/output system (BIOS) thatinteracts with hardware of the special purpose computer, device driversthat interact with particular devices of the special purpose computer,one or more operating systems, user applications, background services,background applications, etc. As such, the one or more processors may beconfigured to execute the processor executable instructions.

The computer programs may include: (i) descriptive text to be parsed,such as HTML (hypertext markup language) or XML (extensible markuplanguage), (ii) assembly code, (iii) object code generated from sourcecode by a compiler, (iv) source code for execution by an interpreter,(v) source code for compilation and execution by a just-in-timecompiler, etc. As examples only, source code may be written using syntaxfrom languages including C, C++, C#, Objective-C, Haskell, Go, SQL, R,Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, Javascript®, HTML5,Ada, ASP (active server pages), PHP, Scala, Eiffel, Smalltalk, Erlang,Ruby, Flash®, Visual Basic®, Lua, and Python®.

Further, at least one embodiment of the invention relates to thenon-transitory computer-readable storage medium including electronicallyreadable control information (processor executable instructions) storedthereon, configured in such that when the storage medium is used in acontroller of a device, at least one embodiment of the method may becarried out.

The computer readable medium or storage medium may be a built-in mediuminstalled inside a computer device main body or a removable mediumarranged so that it can be separated from the computer device main body.The term computer-readable medium, as used herein, does not encompasstransitory electrical or electromagnetic signals propagating through amedium (such as on a carrier wave); the term computer-readable medium istherefore considered tangible and non-transitory. Non-limiting examplesof the non-transitory computer-readable medium include, but are notlimited to, rewriteable non-volatile memory devices (including, forexample flash memory devices, erasable programmable read-only memorydevices, or a mask read-only memory devices); volatile memory devices(including, for example static random access memory devices or a dynamicrandom access memory devices); magnetic storage media (including, forexample an analog or digital magnetic tape or a hard disk drive); andoptical storage media (including, for example a CD, a DVD, or a Blu-rayDisc). Examples of the media with a built-in rewriteable non-volatilememory, include but are not limited to memory cards; and media with abuilt-in ROM, including but not limited to ROM cassettes; etc.Furthermore, various information regarding stored images, for example,property information, may be stored in any other form, or it may beprovided in other ways.

The term code, as used above, may include software, firmware, and/ormicrocode, and may refer to programs, routines, functions, classes, datastructures, and/or objects. Shared processor hardware encompasses asingle microprocessor that executes some or all code from multiplemodules. Group processor hardware encompasses a microprocessor that, incombination with additional microprocessors, executes some or all codefrom one or more modules. References to multiple microprocessorsencompass multiple microprocessors on discrete dies, multiplemicroprocessors on a single die, multiple cores of a singlemicroprocessor, multiple threads of a single microprocessor, or acombination of the above.

Shared memory hardware encompasses a single memory device that storessome or all code from multiple modules. Group memory hardwareencompasses a memory device that, in combination with other memorydevices, stores some or all code from one or more modules.

The term memory hardware is a subset of the term computer-readablemedium. The term computer-readable medium, as used herein, does notencompass transitory electrical or electromagnetic signals propagatingthrough a medium (such as on a carrier wave); the term computer-readablemedium is therefore considered tangible and non-transitory. Non-limitingexamples of the non-transitory computer-readable medium include, but arenot limited to, rewriteable non-volatile memory devices (including, forexample flash memory devices, erasable programmable read-only memorydevices, or a mask read-only memory devices); volatile memory devices(including, for example static random access memory devices or a dynamicrandom access memory devices); magnetic storage media (including, forexample an analog or digital magnetic tape or a hard disk drive); andoptical storage media (including, for example a CD, a DVD, or a Blu-rayDisc). Examples of the media with a built-in rewriteable non-volatilememory, include but are not limited to memory cards; and media with abuilt-in ROM, including but not limited to ROM cassettes; etc.Furthermore, various information regarding stored images, for example,property information, may be stored in any other form, or it may beprovided in other ways.

The apparatuses and methods described in this application may bepartially or fully implemented by a special purpose computer created byconfiguring a general purpose computer to execute one or more particularfunctions embodied in computer programs. The functional blocks andflowchart elements described above serve as software specifications,which can be translated into the computer programs by the routine workof a skilled technician or programmer.

Although described with reference to specific examples and drawings,modifications, additions and substitutions of example embodiments may bevariously made according to the description by those of ordinary skillin the art. For example, the described techniques may be performed in anorder different with that of the methods described, and/or componentssuch as the described system, architecture, devices, circuit, and thelike, may be connected or combined to be different from theabove-described methods, or results may be appropriately achieved byother components or equivalents.

At least one embodiment of the invention relates to a detector apparatuscomprising a scattered radiation grid, a scintillator unit forconverting X-rays into a light quantity, an evaluation unit forconverting the light quantity into electric signals, and amodule-receiving appliance. The scintillator unit and the scatteredradiation grid are mechanically connected to the module-receivingappliance via a first connection. The evaluation unit is mechanicallyconnected to the module-receiving appliance via a second connectionwhich is independent of the first connection. The evaluation unit, thescintillator unit and the scattered radiation grid are aligned withrespect to one another such that the light quantity emitted fromsub-regions of the scintillator unit is registered by sub-regions of theevaluation unit.

In at least one embodiment, the scattered radiation grid can comprisegrid walls or grid openings aligned to focus a radiation source. Thegrid walls can be stepped. The grid openings can be conical or in theshape of a truncated pyramid. The grid openings can have a square orrectangular base. The scattered radiation grid comprises an absorptionmaterial suitable for absorbing X-rays, for example lead or tungsten.The scattered radiation grid can be in one piece.

In at least one embodiment, the scintillator unit comprises sub-regions.The sub-regions can, for example, be defined by septa filled with areflector material. The sub-regions can also be defined by the alignmentor assignment to the scattered radiation grid. The sub-region can be adetector element or a pixel.

In at least one embodiment, the evaluation unit can comprise aphotodiode or a photodiode array and an electronic evaluation unit. Theevaluation unit can comprise a mechanical carrier or a mechanical moduleunit. Further electronic readout and/or evaluation units can be arrangedon the mechanical carrier. The evaluation unit can be connected to themodule-receiving appliance by way of a second connection.

In at least one embodiment, the module-receiving appliance can, forexample, be embodied as a bent, module-receiving appliance with a recessas a detector window. A plurality of scattered radiation grids,scintillator units and evaluation units can be arranged in the recess.The scattered radiation grid, scintillator unit and evaluation unit canin particular be fixed in the direction of rotation on themodule-receiving appliance.

In at least one embodiment, the module-receiving appliance can also be amechanical carrier on which the scattered radiation grid, scintillatorunit and/or evaluation unit can be fixed. It is possible for a pluralityof mechanical carriers to be provided, for example one mechanicalcarrier for the scattered radiation grid and one mechanical carrier forthe evaluation unit. The mechanical carrier can be fixed to themodule-receiving appliance. The mechanical carrier can be comprised bythe module-receiving appliance. The mechanical connection can be formedby screws, locating pins, locating holes or the like. In addition, it ispossible for a groove, a spring or a similarly embodied positive andnegative shape to be used for the mechanical connection or alignment.

X-rays pass through a grid opening of the scattered radiation grid andland on a sub-region of the scintillator unit. In the scintillator unit,the X-rays are converted into a first light quantity. The sub-region ofthe scintillator unit emits a light quantity, preferably the first lightquantity, or the light quantity is coupled out of the scintillator unit.The light quantity lands on a sub-region of the evaluation unit. Thelight quantity can be registered by the sub-region of the evaluationunit.

The alignment of the sub-region of the scintillator unit with thesub-region of the evaluation unit can, for example, be embodied suchthat the two-dimensional orientation of the sub-regions overlaps orcorresponds at least partially, preferably exactly. The surface normalsof the sub-region of the scintillator unit and the evaluation unit canpreferably be parallel. The surface normal can, for example, for asub-region in the center of the scintillator unit, a sub-region in thecenter of the evaluation unit or the scintillator array, point in thedirection of the radiation source. For sub-regions outside the center ofthe scintillator unit or the evaluation unit, the surface normal canpoint approximately, but not exactly, in the direction of the radiationsource.

The sub-region of the scintillator unit and the sub-region of theevaluation unit can have a similar or the same two-dimensionalextension. There can be a gap between the sub-region of the scintillatorunit and the sub-region of the evaluation unit. The gap can beair-filled or filled with an optical filler.

The first connection and/or the second connection can be fixing device.The first connection and the second connection are independent of oneanother. There can be a further connection between the detection unitformed by the scintillator unit and the scattered radiation grid and theevaluation unit, for example in form of a locating pin, locating hole,groove, spring or the like. The further connection can in particular beused for the mutual alignment of the evaluation unit and the detectionunit.

The inventors suggest, in at least one embodiment, a modification of theconstruction of a detector apparatus compared to known detectorapparatuses. The scattered radiation grid can be mechanically connectedto the module-receiving appliance via a first connection, for example,in a fixed or reversible manner. The scattered radiation grid can beproduced in the form of modules, large segments or as one piece. Withmechanical connection or fixing, it is also possible for the gridopenings to be aligned with the tube focus or the radiation source. Thescintillator unit can preferably be mechanically connected to thescattered radiation grid.

Jointly with the scattered radiation grid, the scintillator unit is nolonger connected in a fixed and inseparable way to the evaluation unitor the photodiode array. The module-receiving appliance, the scatteredradiation grid and the scintillator unit advantageously form amechanically stable unit that can remain unchanged after the firstassembly.

Advantageously, the bonding process between the scintillator unit andevaluation unit using special optical adhesives can be dispensed with.As individual components, the scattered radiation grid, the scintillatorunit and the evaluation unit can advantageously have different sizes,thus enabling, for example, area-related efficiency to be optimized inthe individual production processes. If the evaluation unit is replaceddue to electronic failures, advantageously, there is no longer any riskof the scattered radiation grid being damaged. The replacement of theevaluation unit can advantageously be less expensive since now only theevaluation unit is replaced. Advantageously, on the replacement ofevaluation units, it is no longer necessary to pay attention to sortingaccording to scintillator properties; in particular, when replacingcentral evaluation units, the time-consuming “re-setting” of adjacentevaluation units in order to ensure equivalent scintillator propertiesafter the replacement and the installation of new evaluation units atthe edge is no longer necessary.

According to one embodiment of the invention, the first connectionand/or the second connection is a detachable connection. The detachableconnection can be formed by an indirect connection via the firstconnection and the second connection to the module-receiving appliance.

Detachable can mean non-destructive, repeatedly detachable orre-connectable. Detachable can mean that no special tool or no specialconditions, for example temperature, chemical bath or the like isrequired to detach the connection. Detachable can mean that theconnection can advantageously be detached simply and quickly by aservice technician. Detachable can mean that, in fixed condition, theconnection is permanently mechanically stable.

According to one embodiment of the invention, the scintillator unitforms a detection unit with the scattered radiation grid. Thescintillator unit can be connected to the scattered radiation grid. Thedetection unit can be mechanically connected to the module-receivingappliance via the first connection. The scintillator unit and scatteredradiation grid can advantageously be jointly mechanically connected tothe module-receiving appliance via the first connection. Thescintillator unit and scattered radiation grid can advantageously bemechanically connected to one another and aligned in one step before themechanical connection to the module-receiving appliance.

According to one embodiment of the invention, the detection unit and theevaluation unit have different two-dimensional extensions. The surfacenormals of the detector surface or the surface of the detection unit canpreferably point toward the radiation source. The detector surface andthe evaluation unit can have a two-dimensional extension approximatelyin the direction of rotation and phi-direction. The two-dimensionalextension can in particular be a flat two-dimensional extension. Thedetection unit and the evaluation unit can advantageously be produced inextensions which can be produced with good reproducibility duringproduction.

According to one embodiment of the invention, the detection unit isassigned to a plurality of evaluation units. The evaluation units canadvantageously have smaller two-dimensional extensions than thedetection unit. The replacement of an evaluation unit can advantageouslybe less expensive due to the smaller two-dimensional extension.

According to one embodiment of the invention, one sub-region of thescintillator unit is assigned to a cell of the scattered radiation grid.The sub-region of the scintillator unit can be assigned to a gridopening of the scattered radiation grid. The cell of a scatteredradiation grid can be the surface of the grid opening on the side facingthe scintillator unit and have half the thickness or surface of theadjacent grid walls. The sub-region, in particular an active sub-region,can have a two-dimensional extension corresponding to at least thesurface of the grid opening. It is, for example, possible, for septafilled with reflector material to be provided below the grid walls. Thesub-region can also be active below the grid walls. An assignment of thegrid opening to the sub-region of the scintillator unit canadvantageously be achieved.

According to one embodiment of the invention, the sub-region of thescintillator unit and the cell of the scattered radiation grid have thesame two-dimensional extension. The scintillator unit can be subdividedinto sub-regions corresponding to the cell size of the scatteredradiation grid. This can correspond to the pixelation of the detector.The connection of the scintillator unit and the scattered radiation gridis preferably as exact as possible. An unambiguous assignment of thesub-region of the scintillator unit to a cell or a grid opening of thescattered radiation grid can advantageously be achieved.

According to one embodiment of the invention, the sub-region of thescintillator unit is arranged in a grid opening of the scatteredradiation grid. The sub-region of the scintillator unit can be formed asa cube-shaped or square scintillator element. The assignment of thesub-region of the scintillator unit and a grid opening of the scatteredradiation grid is advantageously unambiguous. Faulty adjustment ormisalignment of the sub-region of the scintillator unit and the gridopening of the scattered radiation grid can advantageously be avoided.

According to one embodiment of the invention, the scintillator unitcomprises, for example, GOS, YGO, BGO, LUTAG, CsI, YAG or GGAG. Thescintillator unit can advantageously be produced with a two-dimensionalextension.

According to one embodiment of the invention, the sub-region of thescintillator unit comprises a plurality of needle-shaped scintillatorelements. The scintillator unit can consist of a plurality of thinscintillator needles that can be packed together as tightly as possibleand which have a cross section that can be substantially smaller thanthe sub-region of the scintillator unit or the sub-region of thescattered radiation grid. Advantageously, the requirements for exactalignment of the scattered radiation grid, the scintillator unit and theevaluation unit are lower.

According to one embodiment of the invention, the scintillator elementscomprise, for example, GOS, YGO, BGO, LUTAG, CsI, YAG or GGAG. Thescintillator elements can advantageously be produced in a needle shape.At the same time, the needle-shaped scintillator elements can bearranged perpendicular to the detector surface or two-dimensionalextension of the scintillator unit.

According to one embodiment of the invention, a gap is formed betweenthe scintillator unit and the evaluation unit. A gap can remain betweenthe scintillator unit and the evaluation unit. The height of the gap orthe distance between the scintillator unit and evaluation unit can rangefrom a few micrometers to a few millimeters. The scintillator unit andthe evaluation unit can advantageously be mechanically decoupled.

According to one embodiment of the invention, the gap is filled with afluid. The fluid can be a gas, a liquid or a gel. The gas can, forexample, be air. The light quantity emitted from the sub-region of thescintillator unit can advantageously land on the sub-region of theevaluation unit while subject to as little influence as possible.

According to one embodiment of the invention, the gap is filled with anoptical filler. The optical filler can be transparent to the lightquantity. The optical filler can be a gel or a pad. The light quantityemitted from the sub-region of the scintillator element canadvantageously land on the sub-region of the evaluation unit whilesubject to as little influence as possible. The transportation of thelight from the sub-region of the scintillator unit to the sub-region ofthe evaluation unit in the gap can advantageously be optimized.

According to one embodiment of the invention, the scintillator unitand/or the evaluation unit comprises a fixing device. The fixing devicecan be the first connection or the second connection. The fixing devicecan be formed by an enlargement of the extension of the scintillatorunit or the evaluation unit beyond the region used for the detection ofX-rays. The fixing device can, for example, comprise locating holes,locating pins or drill holes for fixing via screws.

At least one embodiment of the invention further relates to a medicaldevice comprising a detector apparatus according to the invention. Atleast one embodiment of the invention, the medical device is a computedtomography scanner. The advantages of the detector apparatus accordingto at least one embodiment of the invention can be transferred to themedical device. The detector apparatus for the medical device canadvantageously be produced less expensively. Repairs to the detectorapparatus can advantageously be less expensive.

FIG. 1 shows an example embodiment of the detector apparatus accordingto the invention 1 in a first embodiment. The detector apparatus 1comprises a scattered radiation grid 3, a scintillator unit 5 forconverting X-rays into a light quantity, an evaluation unit 9 forconverting the light quantity into electric signals and amodule-receiving appliance 11. The scintillator unit 5 and the scatteredradiation grid 3 are mechanically connected to the module-receivingappliance 11 via a first connection 17. The evaluation unit 9 ismechanically connected to the module-receiving appliance 11 via a secondconnection 19 which is independent of the first connection 17. Themodule-receiving appliance 11 is embodied such that a detector window isparallel to the axis of rotation 43 and the detection unit 7 and theevaluation unit 9 are arranged in the detector window.

The evaluation unit 9, the scintillator unit 5 and the scatteredradiation grid 3 are aligned with respect to one another such that thelight quantity emitted from the sub-regions of the scintillator unit 5is registered by sub-regions of the evaluation unit 9. A gap 13 isformed between the scintillator unit 5 and the evaluation unit 9. Thescintillator unit 5 forms a detection unit 7 with the scatteredradiation grid 3. The indirect connection between the detection unit 7and evaluation unit 9 via the first connection 17 and the secondconnection 19 to the module-receiving appliance 11 is detachable. Thescintillator unit 5 comprises, for example, GOS, YGO, BGO, LUTAG, CsI,YAG or GGAG. The gap 13 can be air-filled or filled with an opticalfiller.

FIG. 2 shows an example embodiment of the arrangement of the scatteredradiation grid 3, scintillator unit 5 and evaluation unit 9 according tothe invention in a first embodiment. The scattered radiation grid 3comprises, for example, three grid openings 4. The scattered radiationgrid 3 comprises cells 16 corresponding to an extension of the gridopening 4 and twice half the wall thickness. The extensions of thesub-region 6 of the scintillator unit 5 and the sub-region 10 ofevaluation unit 9 correspond to the cell 16. In a further embodimentthe, in particular active, sub-region 10 of the evaluation unit 9 can besmaller than the sub-region 6 of the scintillator unit 5, for exampledue to the arrangement of guard rings or protective rings in theevaluation unit.

FIG. 3 shows an example embodiment of the detection unit 7 according tothe invention in a first embodiment in a top view. The top view isdepicted from the direction of view from the radiation source to thedetector apparatus. The top view shows the scattered radiation grid 3with grid openings 4. In the direction of view of the top view, thesub-regions of the scintillator unit are located behind the gridopenings 4.

FIG. 4 shows an example embodiment of the detector apparatus accordingto the invention 1 in a second embodiment. The second embodiment differsfrom the first embodiment of the detector apparatus 1 in that that thescintillator unit 5 is embodied within the scattered radiation grid 3.

FIG. 5 shows an example embodiment of the arrangement of the scatteredradiation grid, scintillator unit and evaluation unit according to theinvention in a second embodiment. The sub-region 6 of the scintillatorunit 5 is embodied in a grid opening 4 of the scattered radiation grid.The cube-shaped or square scintillator element extends as far as thegrid walls; the height of the scintillator element is preferably lessthan the slot height of the grid opening.

FIG. 6 shows an example embodiment of the detection unit 7 according tothe invention in a second embodiment in a top view. The secondembodiment differs from the first embodiment of the detection unit 7 inthat that the scintillator unit 5 is embodied within the grid openings 4of the scattered radiation grid 3.

FIG. 7 shows an example embodiment of the sub-region 6 of a scintillatorunit 5 according to the invention. The sub-region 6 of the scintillatorunit 5 comprises a plurality of needle-shaped scintillator elements 21.The scintillator unit 5 consists of a plurality of thin scintillatorneedles that are packed together as tightly as possible and which have across section that is substantially smaller than the sub-region 6 of thescintillator unit 5 or the grid opening 4 of the scattered radiationgrid 3. The needle-shaped scintillator elements 21 comprise, forexample, GOS, YGO, BGO, LUTAG, CsI, YAG or GGAG. The scintillatorelements 21 can be arranged regularly or irregularly. Individualscintillator elements 21 can also be located in the marginal region ofthe sub-region 6 and overlap an adjacent sub-region.

FIG. 8 shows an example embodiment of the detector apparatus accordingto the invention 1 according to a third embodiment. The detectorapparatus 1 comprises a module-receiving appliance 11. In themodule-receiving appliance 11, a plurality of evaluation units 9 anddetection units 7 are arranged in a detector window 24 along thephi-direction 44. The X-rays are emitted from the radiation source 37and land on the detection units 7. The direction of the X-rays isindicated by the lines emerging from the radiation source 37.

FIG. 9 shows an example embodiment of the arrangement of the scatteredradiation grid 3, scintillator unit 5 and evaluation unit 9 according tothe invention in a third embodiment. A plurality of evaluation units 9of a detection unit 7 formed by the scintillator unit 5 and scatteredradiation grid 3 is assigned in the phi-direction 44.

FIG. 10 shows a first example embodiment of the computed tomographyscanner 31 according to the invention in a first embodiment. Thedetector apparatus 1 comprises, for example, two detection units 7 witha scintillator unit 5 and scattered radiation grid 3. Each detectionunit 7 is, for example, assigned two evaluation units 9. The detectionunits 7 and the evaluation units 9 are each arranged along the phi-axis44. The radiation source 37 emits X-rays that are attenuated through thepatient 39. The patient 39 is arranged along the direction of rotation43.

FIG. 11 shows an example embodiment of the computed tomography scanner31 according to the invention with a detector apparatus according to theinvention 1. The detector apparatus 1 can comprise a plurality ofdetector modules comprising at least one X-ray detector. The detectormodules preferably comprise a plurality of X-ray detectors in atwo-dimensional matrix or arrangement. The computed tomography scanner31 contains a gantry 33 with a rotor 35. The rotor 35 comprises an X-raysource 37 and the detector apparatus according to the invention 1. Thepatient 39 is mounted on the patient bed 41 and can be moved along theaxis of rotation z 43 through the gantry 33. A computing unit 45 is usedto control and calculate the sectional views. An input appliance 47 andan output apparatus 49 are connected to the computing unit 45.

Although the invention was described in more detail by the preferredexample embodiments, the invention is not restricted by the examplesdisclosed and other variations can be derived herefrom by the personskilled in the art without departing from the scope of protection of theinvention.

The patent claims of the application are formulation proposals withoutprejudice for obtaining more extensive patent protection. The applicantreserves the right to claim even further combinations of featurespreviously disclosed only in the description and/or drawings.

References back that are used in dependent claims indicate the furtherembodiment of the subject matter of the main claim by way of thefeatures of the respective dependent claim; they should not beunderstood as dispensing with obtaining independent protection of thesubject matter for the combinations of features in the referred-backdependent claims. Furthermore, with regard to interpreting the claims,where a feature is concretized in more specific detail in a subordinateclaim, it should be assumed that such a restriction is not present inthe respective preceding claims.

Since the subject matter of the dependent claims in relation to theprior art on the priority date may form separate and independentinventions, the applicant reserves the right to make them the subjectmatter of independent claims or divisional declarations. They mayfurthermore also contain independent inventions which have aconfiguration that is independent of the subject matters of thepreceding dependent claims.

None of the elements recited in the claims are intended to be ameans-plus-function element within the meaning of 35 U.S.C. §112(f)unless an element is expressly recited using the phrase “means for” or,in the case of a method claim, using the phrases “operation for” or“step for.”

Example embodiments being thus described, it will be obvious that thesame may be varied in many ways. Such variations are not to be regardedas a departure from the spirit and scope of the present invention, andall such modifications as would be obvious to one skilled in the art areintended to be included within the scope of the following claims.

What is claimed is:
 1. A detector apparatus, comprising: a scatteredradiation grid; a scintillator unit to convert X-rays into a lightquantity; an evaluation unit to convert the light quantity into electricsignals; and a module-receiving appliance, the scintillator unit and thescattered radiation grid being mechanically connected to themodule-receiving appliance via a first connection, the evaluation unitbeing mechanically connected to the module-receiving appliance via asecond connection, independent of the first connection, and theevaluation unit, the scintillator unit and the scattered radiation gridbeing aligned with respect to one another such that the light quantity,when emitted from sub-regions of the scintillator unit, is registered bysub-regions of the evaluation unit.
 2. The detector apparatus of claim1, wherein at least one of the first connection and the secondconnection is a detachable connection.
 3. The detector apparatus ofclaim 1, wherein the scintillator unit forms a detection unit with thescattered radiation grid.
 4. The detector apparatus of claim 1, whereinthe detection unit and the evaluation unit have differenttwo-dimensional extensions.
 5. The detector apparatus of claim 1,wherein the detection unit is assigned to a plurality of evaluationunits.
 6. The detector apparatus of claim 1, wherein one sub-region ofthe sub-regions of the scintillator unit is assigned to a cell of thescattered radiation grid.
 7. The detector apparatus of claim 6, whereinthe one sub-region of the sub-regions of the scintillator unit and thecell of the scattered radiation grid have the same two-dimensionalextension.
 8. The detector apparatus of claim 6, wherein the onesub-region of the sub-regions of the scintillator unit is formed in agrid opening of the scattered radiation grid.
 9. The detector apparatusof claim 6, wherein the one sub-region of the sub-regions of thescintillator unit comprises a plurality of needle-shaped scintillatorelements.
 10. The detector apparatus of claim 1, wherein a gap is formedbetween the scintillator unit and the evaluation unit.
 11. The detectorapparatus of claim 10, wherein the gap is filled with a fluid.
 12. Thedetector apparatus of claim 10, wherein the gap is filled with anoptical filler.
 13. A medical device, comprising: a detector apparatusof claim
 1. 14. The medical device of claim 13, wherein the medicaldevice is a computed tomography scanner.
 15. The detector apparatus ofclaim 2, wherein the scintillator unit forms a detection unit with thescattered radiation grid.
 16. The detector apparatus of claim 2, whereinthe detection unit and the evaluation unit have differenttwo-dimensional extensions.
 17. The detector apparatus of claim 2,wherein the detection unit is assigned to a plurality of evaluationunits.
 18. The detector apparatus of claim 2, wherein one sub-region ofthe sub-regions of the scintillator unit is assigned to a cell of thescattered radiation grid.
 19. A medical device, comprising: a detectorapparatus of claim
 6. 20. The medical device of claim 19, wherein themedical device is a computed tomography scanner.